<!--Vue的DOM监听-->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <script src="https://cdn.jsdelivr.net/npm/vue@2.5.16/dist/vue.min.js"></script>
</head>
<body>
  <div id="one">
    <input type="text" v-model="text_value_1">
    <span>{{text_value_1}}</span>
  </div>
  <script>
    var vm = new Vue({
      el:"#one",
      data:{
        text_value_1:"",
      }
    });
  </script>
</body>
</html>